Dear Archana,

According to the previous year cut off of state Quota for general category student for the state of Karnataka your cousin has a chance to get any government medical College in Karnataka since the cut off is below 485 but for bangalore medical college the cut off is 512. Though keep in mind that the cut off fluctuates each year and may change for this year as well 

https://medicine.careers360.com/articles/neet-cutoff-karnataka

This year NEET cut-off rose like hell due to easy paper compared to previous years and seats were also not increased that much. That's the reason of not getting good rank even with decent marks. If I talk about Bangalore Medical College then by previous years data round 1 closing rank in 2017 was 779 for unreseved category and for round 2 it was 1835. So there is no chance of getting BMC with 58235 rank.